The most precise ever laser satellite measurement method provides new clues to relativity

Tides on Earth have a far-reaching influence, including disturbing satellites’ measurements by affecting their motion. This disturbance can be studied using a model for the gravitational potential of the Earth, taking into account the fact that Earth’s shape is not spherical. The LAser RElativity Satellite (LARES), is the best ever relevant test particle to move in the Earth’s gravitational field. In a new study published in EPJ Plus, LARES proves its efficiency for high-precision probing of General Relativity and fundamental physics. By studying the Earth’s tidal perturbations acting on the LARES, Vahe Gurzadyan from the Center for Cosmology and Astrophysics at Yerevan State University, Armenia, and colleagues demonstrate the value of laser-range satellites for high-precision measurements.

The papers published in this Focus Point evidence the broad range of interests pursued by the Italian community active in the field of Planetary Sciences.

Although this selection of papers can by no means be considered to exhaustively represent the fields of interest of the community, many points of interests and activities are included, from PI activitities in Planetary Space Missions, both from ESA and NASA programmes (such as Bepi Colombo and Juno) to the study of physical and dynamical properties of minor bodies to the geological study of planetary surfaces to the study of atmospheres to cosmogeophysical studies of meteorites.

The Italian Research Institutes, Observatories and Universities hosting research groups active in Planetary Sciences are based in different regional locations on the Italian territory as also shown by the selection of articles published in this Focus Point, and are evidence of a growing interest of the Astrophysical Community in Planetary Sciences and of a rapid growth in the number of topics investigated and in the number of scientists involved.

New study shows that two seemingly diverging theories of ever-increasing disorder, known as entropy, can be tested against each other experimentally in the smallest possible systems

Have you ever tried turning the spoon back after stirring jam into a rice pudding? It never brings the jam back into the spoon. This ever-increasing disorder is linked to a notion called entropy. Entropy is of interest to physicists studying the evolution of systems made up of multiple identical elements, like gas. Yet, how the states in such systems should be counted is a bone of contention. The traditional view developed by one of the fathers of statistical mechanics, Ludwig Boltzmann - who worked on a very large number of elements - is opposed to the seemingly disjointed theoretical perspective of another founding scientists of the discipline, Willard Gibbs, who describes systems with a very small number of elements. In a new study published in EPJ Plus, Loris Ferrari from the University of Bologna, Italy, demystifies this clash between theories by analysing the practical consequences of Gibbs’ definition in two systems of a well-defined size. Ferrari speculates about the possibility that, for certain quantities, the differences resulting from Boltzmann's and Gibbs' approach can be measured experimentally.

SA new study uses a combination of glacial morphology and remote sensing measurement to explore the role of ice in shaping Martian landslides

How good is your Martian geography? Does Valles Marineris ring a bell? This area is known for having landslides that are among the largest and longest in the entire solar system. They make the perfect object of study due to their steep collapse close to the scarp, extreme thinning, and long front runout. In a new research paper published in EPJ Plus, Fabio De Blasio and colleagues from Milano-Bicocca University, Italy, explain the extent to which ice may have been an important medium of lubrication for landslides on Mars. This can in turn help us understand the geomorphological history of the planet and the environment of deposition.

How to bring an asteroid back nearer to lunar orbit. Credits: Keck Institute for Space Studies report

Study reviews the state-of-the-art in polarimetry as a remote sensing technique for the small bodies in our solar system

The solar system is full of various small bodies such as planetary moons, main belt asteroids, Jupiter Trojans, Centaurs, trans-Neptunian objects and comets. To study them, scientists typically analyse the radiation they reflect, which is referred to as polarimetry. Scientists not only focus on the intensity of the scattered radiation, but also on how photons oscillate in the plane perpendicular to their direction of propagation - that is, their polarisation. Combining these two aspects yields significantly better descriptions than data obtained from the intensity alone. In a paper published in EPJ Plus, Stefano Bagnulo from Armagh Observatory and Planetarium in Northern Ireland, UK, and colleagues review the state-of-the-art in polarimetry for studying the small bodies in our solar system.

New mathematical model for cryptosporidiosis - HIV co-infection explores their synergistic relationship in connection with prevention and treatment

One of the most common waterborne diseases worldwide is cryptosporidiosis, a parasitic disease affecting the small intestine and possibly our airways. It is a common cause of diarrhoea in HIV-positive patients, who are known to have lower immunity. Now Kazeem Oare Okosun from Vaal University of Technology in South Africa and colleagues from Pakistan and Nigeria have developed a new model and numerical simulations to determine the optimal combination of prevention and treatment strategies for controlling both diseases in patients who have been co-infected. Their results, recently published in EPJ Plus, show a positive impact on the treatment and prevention for cryptosporidiosis alone, for HIV-AIDS alone, or for both together.

During the past decades, new nuclear systems have been designed with the goals of ensuring the sustainability of nuclear energy, minimizing long-lived radioactive waste and improving the safety of nuclear reactors. This has led to the request for new or more precise nuclear data, either because reactions on isotopes neglected before have become important, or because new types of reactions have to be described. Nuclear data are in fact all the quantities necessary to describe the nuclear reactions occurring in a system.

In Europe, an important effort has been devoted to the collection of high quality nuclear data, and partially supported by the EURATOM framework programs: in particular ANDES (Accurate Nuclear Data for nuclear Energy Sustainability) and CHANDA (solving CHAllenges in Nuclear Data) in FP7. This EPJ Plus Focus Point issue presents part of the work performed during these programs.

All articles are freely accessible until 30 September 2017. For further information read the Editorial

Future space exploration aims to fly further from Earth than ever before. Now, Italian Space Agency scientists have expressed an interest in contributing to the development of robotic technologies to bring an asteroid from beyond lunar orbit back into closer reach in order to better study it. In a paper published in EPJ Plus, Marco Tantardini and Enrico Flamini from the Italian Space Agency (ASI) make the case for taking part in the robotic phase of the Asteroid Redirect Mission (ARM). In addition to taking manned spaceflights deeper into space than ever before, the proposed mission would also bring some benefit for planetary science.

Three dimensional reconstruction of the sample analysed using white beam neutron tomography.

Combining neutron and X-ray imaging gives clues to how ancient weapons were manufactured

Since the 19th century, collectors have become increasingly interested in weapons from ancient Asia and the Middle East. In an attempt to fight forged copies, physicists are now adding their imaging power to better authenticate these weapons; the fakes can't resist the investigative power of X-rays combined with neutron imaging. In a study published in EPJ Plus, an Italian team, working in close collaboration with the Wallace Collection in London and the Neutron Imaging team at the Helmholtz Zentrum Berlin, has demonstrated the usefulness of such a combined imaging approach to help museum curators in their quest to ensure authenticity. Filament Salvemini, currently affiliated with the Australian Centre for Neutron Scattering ACNS at ANSTO in Lucas Heights near Sydney, and colleagues can now reliably tell first-class modern copies of early daggers and swords from authentic ones.

Initially motivated by the celebration of the international year of Crystallography in 2014, This EPJ Plus focus point issue presents a coherent collection of papers summarizing the status of third generation synchrotron beamlines devoted to crystallography in most European facilities and in an invited extraeuropean one: 9 papers for 9 facilities. Standard organization of information, emphasis on technical details and design choices, many pictures and schematics, are some of the attractive ingredients offered herein. The reader may find references to more than 50 beamlines available or planned in the close future for crystallography experiments, detailed technical descriptions of 17 beamlines, additional information about complementary aspects such as user access, laboratory support or computational tools and scientific highlights. Last but not least, looking through the papers one may get key hints on the future directions as planned by the different facilities. Altogether, a tool to have a global view of crystallography beamlines in a very significant subset of the worldwide synchrotron network.

The articles are freely accessible until 15 July. For further information read the Editorial